1. Field of the Invention
The present invention relates to a sound motion picture projection apparatus, more particularly to a sound motion picture projection apparatus having a sound recording and reproducing film path, a sound recording and reproducing magnetic head disposed along said sound film path and a head pad movable between a film pressing position at which position the head pad presses a film against a magnetic head and a film pressure releasing position at which position the head pad releases the pressing of the film, and enabling reproduction and/or recording of sound information in synchronism with projection of picture images and further enabling automatic film loading from a picture projection station to the sound recording and reproducing film path.
2. Description of the Prior Art
Most of the conventional sound motion picture projection apparatus capable of automatic film loading is so designed that at the time of film loading, at first, an operation mode change-over dial is changed to a film loading position so as to actuate an intermittent film feed mechanism provided at the picture projection station as well as a continuous film feed means, such as sprocket driven by a motor, provided along the sound film path and at the termination of the film loading the operation mode change-over dial is further changed to a projection position so as to carry out the projection and the sound reproduction (and/or recording).
In the sound motion picture projection apparatus constructed as mentioned above, when the operation mode change-over dial is set to the film loading position, the head pad is kept away from the magnetic head to facilitate film loading and a capstan provided after the magnetic head and connected with a fly wheel for stabilizing the film speed and a pinch roller for pressing the film against the capstan are also kept apart from each other, while when the operation mode change-over dial is changed from the film loading position to the projection position, the magnetic head and the head pad as well as the capstan and the pinch roller are pressed against each other, holding the film therebetween so as to carry out the picture projection and the sound reproduction (and/or the sound recording). However, according to such a construction of the sound motion picture projection apparatus, it is necessary for the operator, at the time of projection start, to operate the operation mode change-over dial, after having confirmed that the film has been correctly loaded, and especially take care when the operation mode change-over dial is changed from the film loading position to the picture projection position. Namely, in case such a misoperation is carried out that the operation mode change-over dial is changed to the picture projection position while the leader part of the film has not yet reached the magnetic head in the sound film path or the sprocket for the continuous film feeding or that the film is loaded while the operation mode change-over dial has been changed to the picture projection position, there is a danger that the film transported from the picture projection station by means of the intermittent film feed mechanism, jams at the magnetic head and the head pad, because, at this time the magnetic head and the head pad have already been pressed against each other and thereby the film could not be loaded and moreover be damaged.
In consequence it is quite desirable to improve the sound motion picture projection apparatus of this kind in such a manner that despite the misoperation by the operator of the apparatus the film can be surely and correctly loaded automatically and the projection can always be carried out in a normal way.